--- /dev/null
+# Documentation WiringPi-library
+
+The WiringPi-library enables access to the GPIO pins of the Raspberry PI. In this documentation you will find information about the available functions and their use.
+Since Version 3, extensions have now been carried out again at the interface.In the case of new implementations, you should rely on the current nine functions.
+The old [GPIO Sysfs Interface for Userspace](https://www.kernel.org/doc/Documentation/gpio/sysfs.txt) is no longer supported.
+
+**Attention:** This documentation is still in progress and therefore incomplete.
+The content of this documentation was created with care and to the best of our knowledge and belief. However, the authors do not guarantee the correctness, completeness and topicality of the information provided.The content of the documentation is used at your own risk.
+No liability is generally assumed for damage caused by material or intangible nature caused by the use or non-use of the information provided or by the use of incorrect and incomplete information.
+
+## Installation
+
+Unfortunately, the WiringPi Library is not available directly in Raspberry Pi OS, which is why it has to be installed manually.
+Either you can download a Debian package or translate it manually.
+**Create Debian package:**
+
+```bash
+sudo apt install git
+git clone https://github.com/WiringPi/WiringPi.git
+cd WiringPi
+./build debian
+mv debian-template/wiringpi-3.0-1.deb .
+```
+
+**Install Debian package:**
+
+```bash
+sudo apt install ./wiringpi-3.0-1.deb
+```
+
+**Uninstall Debian package:**
+
+```bash
+sudo apt purge wiringpi
+```
+
+
+## PIN Numbering and Raspberry Pi Models
+
+GPIOs: https://pinout.xyz/pinout/wiringpi
+
+**Raspberry Pi Models with 40-Pin GPIO J8 Header:**
+
+ | BCM | WPI | Name | Physical | Name | WPI | BCM |
+ |-----|-----|---------|:---------:|---------|-----|-----|
+ | | | 3V3 | 1 I 2 | 5V | | |
+ | 2 | 8 | SDA.1 | 3 I 4 | 5V | | |
+ | 3 | 9 | SCL.1 | 5 I 6 | GND | | |
+ | 4 | 7 | GPIO. 7 | 7 I 8 | TxD | 15 | 14 |
+ | | | GND | 9 I 10 | RxD | 16 | 15 |
+ | 17 | 0 | GPIO. 0 | 11 I 12 | GPIO. 1 | 1 | 18 |
+ | 27 | 2 | GPIO. 2 | 13 I 14 | GND | | |
+ | 22 | 3 | GPIO. 3 | 15 I 16 | GPIO. 4 | 4 | 23 |
+ | | | 3V3 | 17 I 18 | GPIO. 5 | 5 | 24 |
+ | 10 | 12 | MOSI | 19 I 20 | GND | | |
+ | 9 | 13 | MISO | 21 I 22 | GPIO. 6 | 6 | 25 |
+ | 11 | 14 | SCLK | 23 I 24 | CE0 | 10 | 8 |
+ | | | GND | 25 I 26 | CE1 | 11 | 7 |
+ | 0 | 30 | SDA.0 | 27 I 28 | SCL.0 | 31 | 1 |
+ | 5 | 21 | GPIO.21 | 29 I 30 | GND | | |
+ | 6 | 22 | GPIO.22 | 31 I 32 | GPIO.26 | 26 | 12 |
+ | 13 | 23 | GPIO.23 | 33 I 34 | GND | | |
+ | 19 | 24 | GPIO.24 | 35 I 36 | GPIO.27 | 27 | 16 |
+ | 26 | 25 | GPIO.25 | 37 I 38 | GPIO.28 | 28 | 20 |
+ | | | GND | 39 I 40 | GPIO.29 | 29 | 21 |
+
+
+**Raspberry Pi 1B Rev. 2 with 26-Pin GPIO P1 Header:**
+
+ | BCM | WPI | Name | Physical | Name | WPI | BCM |
+ |-----|-----|---------|:--------:|----------|-----|-----|
+ | | | 3V3 | 1 I 2 | 5V | | |
+ | 2 | 8 | SDA.1 | 3 I 4 | 5V | | |
+ | 3 | 9 | SCL.1 | 5 I 6 | GND | | |
+ | 4 | 7 | GPIO. 7 | 7 I 8 | TxD | 15 | 14 |
+ | | | GND | 9 I 10 | RxD | 16 | 15 |
+ | 17 | 0 | GPIO. 0 | 11 I 12 | GPIO. 1 | 1 | 18 |
+ | 27 | 2 | GPIO. 2 | 13 I 14 | GND | | |
+ | 22 | 3 | GPIO. 3 | 15 I 16 | GPIO. 4 | 4 | 23 |
+ | | | 3V3 | 17 I 18 | GPIO. 5 | 5 | 24 |
+ | 10 | 12 | MOSI | 19 I 20 | GND | | |
+ | 9 | 13 | MISO | 21 I 22 | GPIO. 6 | 6 | 25 |
+ | 11 | 14 | SCLK | 23 I 24 | CE0 | 10 | 8 |
+ | | | GND | 25 I 26 | CE1 | 11 | 7 |
+
+
+
+**Raspberry Pi 1B Rev. 1 with 26-Pin GPIO P1 Header:**
+
+ | BCM | WPI | Name | Physical | Name | WPI | BCM |
+ |-----|-----|---------|:--------:|---------|-----|-----|
+ | | | 3V3 | 1 I 2 | 5V | | |
+ | 0 | 8 | SDA.0 | 3 I 4 | 5V | | |
+ | 1 | 9 | SCL.0 | 5 I 6 | GND | | |
+ | 4 | 7 | GPIO. 7 | 7 I 8 | TxD | 15 | 14 |
+ | | | GND | 9 I 10 | RxD | 16 | 15 |
+ | 17 | 0 | GPIO. 0 | 11 I 12 | GPIO. 1 | 1 | 18 |
+ | 21 | 2 | GPIO. 2 | 13 I 14 | GND | | |
+ | 22 | 3 | GPIO. 3 | 15 I 16 | GPIO. 4 | 4 | 23 |
+ | | | 3V3 | 17 I 18 | GPIO. 5 | 5 | 24 |
+ | 10 | 12 | MOSI | 19 I 20 | GND | | |
+ | 9 | 13 | MISO | 21 I 22 | GPIO. 6 | 6 | 25 |
+ | 11 | 14 | SCLK | 23 I 24 | CE0 | 10 | 8 |
+ | | | GND | 25 I 26 | CE1 | 11 | 7 |
+
+
+**References**
+Note the different PIN numbers and the I2C0 at Raspberry Pi 1b Rev. 1!
+
+## Initialization
+At the beginning, the WiringPi Library must be initialized.
+To do this, one of the following functions must be called up:
+
+Outdated functions (no longer use):
+
+``wiringPiSetup`` uses Wiringpi numbering (WPI) of the GPIO's and accesses the GPIO register directly.
+``wiringPiSetupGpio`` uses BCM numbering of the GPIOs and accesses the GPIO registers directly.
+``wiringPiSetupPhys`` uses physical PIN numbering of the GPIOs and accesses the GPIO register directly.
+``wiringPiSetupSys`` uses BCM numbering and calls the new function ``wiringPiSetupGpioDevice`` from version 3.4 to ensure compatibility with new core. In version 2, the virtual file system/SYS/Class/GPIO was used. However, the GPIO's exports had to take place externally before the initialization! The function is outdated and should not be used!
+
+**From Version 3.4:**
+``wiringPiSetupPinType`` decides whether WiringPi, BCM or physical PIN numbering is now used, based on the parameter pinType. So it combines the first 3 setup functions together.
+``wiringPiSetupGpioDevice`` is the successor to the ``wiringPiSetupSys`` function and now uses "GPIO Character Device Userspace API" in version 1 (from kernel 5.10). More information can be found at [docs.kernel.org/driver-api/gpio/driver.html](https://docs.kernel.org/driver-api/gpio/driver.html) on the parameter pintype, it is again decided which pin numbering is used.
+With this variant, the GPIO storage (DMA) is not accessed directly, but via a kernel interface that is available with user rights.The disadvantage is the scope of functions and low performance.
+
+<!-- Attention code that uses the nine functions is no longer compatible with the older library version 2! -->
+
+### wiringPiSetup V2 (outdated)
+
+Inializating WiringPi in a classic way.
+>>>
+```C
+int wiringPiSetupGpio(void)
+```
+
+``Return Value``: Error status
+
+> 0 ... No Error
+
+**Example:**
+
+```C
+wiringPiSetupGpio();
+```
+
+### wiringPiSetup V3
+
+Initializing WiringPi.
+>>>
+```C
+int wiringPiSetupPinType(enum WPIPinType pinType)
+```
+
+``pinType``: Type of PIN numbering...
+
+ - `WPI_PIN_BCM` ... BCM-Numbering
+
+ - `WPI_PIN_WPI` ... WiringPi-Numbering
+
+ - `WPI_PIN_PHYS` ... Physical Numbering
+
+``Return Value``: Error status
+
+> 0 ... No Error
+> -1 ... Invalid Parameter Error
+
+**Example:**
+
+```C
+wiringPiSetupPinType(WPI_PIN_BCM);
+```
+
+## Basic Functions
+
+### pinMode
+
+Changes the mode of a GPIO pins.
+>>>
+```C
+void pinMode(int pin, int mode)
+```
+
+``Pin``: The desired PIN (BCM, Wiringpi or PIN number).
+``Mode``: The desired pin mode...
+
+- `INPUT` ... entrance
+
+- `OUTPUT` ... output
+
+- `PWM_OUTPUT` ... PWM output (frequency and pulse break ratio can be configured)
+
+- `PWM_MS_OUTPUT` ... PWM output with MS (Mark/Space) (from version 3)
+
+- `PWM_BAL_OUTPUT` ... PWM output with mode balanced) (from version 3)
+
+- `GPIO_CLOCK` ... Frequency output
+
+- `PM_OFF` ... Approval
+
+**Example:**
+
+```C
+pinMode(17, OUTPUT);
+```
+
+**Support:**
+`PM_OFF` resets the GPIO (Input) and releases it. PWM is ended.
+Raspberry Pi 5 does not support the PWM Bal (Balanced) mode. The MS mode is activated at `PWM_OUTPUT`.
+`GPIO_CLOCK` is currently not yet supported in Raspberry Pi 5 (RP1).
+
+**PWM Exit**
+`PWM_OUTPUT` Activates the specified PWM output with the settings:
+
+ - Mode: BAL-Balanced (Pi0-4), MS-Mark/Space (Pi 5)
+
+ - Range: 1024
+
+ - Divider: 32
+
+In order to make sure that the output starts without an active frequency, you should execute ``pwmWrite(PWM_GPIO, 0);`` before activating.
+After that, the corresponding clock and range values can be adapted, without a frequency already being output unintentionally.
+
+### pinMode
+
+### digitalWrite
+
+Set the value of a GPIO pin.
+>>>
+```C
+void digitalWrite(int pin, int value)
+```
+
+``pin``: The desired Pin (BCM-, Wiringpi- or PIN number).
+``value``: The logical value...
+
+ - `HIGH` ... Value 1 (electrical ~ 3.3 V)
+
+ - `LOW` ... Value 0 (electrical ~0 V / GND)
+
+**Example:**
+
+```C
+pinMode(17, OUTPUT);
+DigitalWrite(17, HIGH);
+```
+
+### pullUpDnControl
+
+Changes the internal pull-up / pull-down resistance.
+>>>
+```C
+void pullUpDnControl (int pin, int pud)
+```
+
+``pin``: The desired Pin (BCM-, WiringPi-, or Pin-number).
+``pud``: The resistance type...
+
+ - `PUD_OFF` ... No resistance
+
+ - `PUD_UP` ... Pull-Up resistance (~50 kOhm)
+
+ - `PUD_DOWN` ... Pull-Down resistance (~50 kOhm)
+
+**Example:**
+
+```C
+pullUpDnControl(17, PUD_DOWN);
+```
+
+### digitalRead
+
+Reads the value of one GPIO-Pin.
+>>>
+```C
+int digitalRead(int pin)
+```
+
+``pin``: The desired Pin (BCM-, WiringPi-, or Pin-number).
+``Return Value``: The logical value.
+
+> `HIGH` ... Value 1
+> `LOW` ... Value 0
+
+**Example:**
+
+```C
+pinMode(17, INPUT);
+pullUpDnControl(17, PUD_DOWN);
+
+int value = digitalRead(17);
+
+if (value == HIGH)
+{
+ // Your Code
+}
+```
+
+## Interrupts
+
+### wiringPiISR
+
+Register an Interrupt Service Routine (ISR) or function that is executed when switching edge.
+
+>>>
+```C
+int wiringPiISR(int pin, int mode, void (*function)(void));
+```
+
+``pin``: The desired Pin (BCM-, WiringPi-, or Pin-number).
+``mode``: Triggering edge mode...
+
+ - `INT_EDGE_RISING` ... Rising edge
+
+ - `INT_EDGE_FALLING` ... Falling edge
+
+ - `INT_EDGE_BOTH` ... Rising and falling edge
+
+``*function``: Function pointer for ISR
+``Return Value``:
+
+> 0 ... Successful
+
+<!-- > <>0 ... Error not implemented at the moment. -->
+
+For example see **wiringPiISRStop**.
+
+
+### wiringPiISRStop
+
+Deregisters the Interrupt Service Routine (ISR) on a Pin.
+
+>>>
+```C
+int wiringPiISRStop (int pin)
+```
+
+``pin``: The desired Pin (BCM-, WiringPi-, or Pin-number).
+``Return Value``:
+
+> 0 ... Successful
+
+<!-- > <>0 ... Error not implemented at the moment. -->
+
+
+**Example:**
+
+```C
+static volatile int edgeCounter;
+
+static void isr(void) {
+ edgeCounter++;
+}
+
+int main (void) {
+ wiringPiSetupPinType(WPI_PIN_BCM);
+ edgeCounter = 0;
+
+ wiringPiISR (17, INT_EDGE_RISING, &isr);
+
+ Sleep(1000);
+ printf("%d rinsing edges\n", );
+
+ wiringPiISRStop(17);
+}
+```
+
+
+### waitForInterrupt
+
+Wait for a call to the Interrupt Service Routine (ISR) with timeout.
+
+>>>
+```C
+int waitForInterrupt (int pin, int mS)
+```
+
+``pin``: The desired Pin (BCM-, WiringPi-, or Pin-number).
+``mS``: Timeout in milliseconds.
+``Return Value``: Error
+> 0 ... Successful
+> -1 ... GPIO Device Chip not successfully opened
+> -2 ... ISR was not registered (WiringPiISR must be called)
+
+
+## Hardware Pulse Width Modulation (PWM)
+
+Available GPIOs: https://pinout.xyz/pinout/pwm
+
+### pwmWrite
+
+Changes the PWM value of the pin. Possible values are 0 -> { PWM Range }.
+>>>
+```C
+pwmWrite(int pin, int value)
+```
+
+``pin``: The desired Pin (BCM-, WiringPi-, or Pin-number).
+``value``: PWM value
+
+### pwmSetRange
+
+Set the range for the PWM value of all PWM pins or PWM channels.
+19200 / divisor / range applies to the calculation of the PWM frequency (m/s mode).
+If ``pinMode(pin, PWM_OUTPUT)`` The value 1024 is automatically set for the divider.
+>>>
+```C
+pwmSetRange (unsigned int range)
+```
+
+``range``: PWM Range
+
+### pwmSetMode
+
+Set the PWM mode for all PWM pins or PWM channels.
+>>>
+```C
+pwmSetMode(int mode);
+```
+
+``mode``: PWM Mode
+
+ - `PWM_MODE_MS` ... Mark / Space Mode (PWM Fixed Frequency)
+
+ - `PWM_MODE_BAL` ... Balanced Mode (PWM Variable Frequency)
+
+**Support:**
+Raspberry Pi 5 does not support the balanced mode!
+
+
+### pwmSetClock
+
+Set the divider for the basic PWM. The base clock is standardized for all Raspberry Pi's to 1900 kHz.
+19200 / divisor / range applies to the calculation of the PWM frequency (m/s mode).
+If ``pinmode(pin, PWM_OUTPUT)`` The value 32 is automatically set for the divider.
+>>>
+```C
+pwmSetClock(int divisor)
+```
+
+``divisor``: Divider (Raspberry Pi 4: 1-1456, all other 1-4095)
+
+- `0` ... Deactivates the PWM clock on Raspberry Pi 5, with other Pi's divisor `1` is used
+
+**Support:**
+Due to its higher internal basic clock, the Raspberry Pi 4 only has a setting range of `1 - 1456`.
+Otherwise, `0 - 4095` applies to a valid divider.
+
+**Example:**
+
+```C
+int main (void) {
+ wiringPiSetupGpio() ;
+
+ pwmSetRange(1024);
+ pwmSetClock(35);
+
+ pwmWrite(18, 512);
+
+ pinMode(18, PWM_MS_OUTPUT);
+
+ double freq = 19200.0 / (double)pwmc / (double)pwmr;
+
+ printf("PWM 50%% @ %g kHz", freq);
+ delay(250);
+
+ pinMode(18, PM_OFF);
+}
+```
+
+
+## I2C - Bus
+
+``wiringPiI2CRawWrite`` and ``wiringPiI2CRawRead`` are the new functions of version 3 with which I2C data can now be sent and read.
+The other writing and reading functions use the SMBUS protocol, which is usually used for I2C chips.
+
+### wiringPiI2CSetup
+
+Open the default I2C bus on the Raspberry Pi and addresses the specified device / slave.
+
+>>>
+```C
+wiringPiI2CSetup(const int devId)
+```
+
+``devId``: I2C-Gerät / Slave Adresse.
+``Return Value``: File Handle to I2C-Bus
+
+> -1 ... Error or EXIT (Programm termination)
+
+**Example**
+>>>
+```C
+int fd = wiringPiI2CSetup(0x20);
+```
+
+### wiringPiI2CSetupInterface
+
+Open the specimen I2C bus and address the specified I2C device / slave.
+>>>
+```C
+wiringPiI2CSetupInterface(const char *device, int devId)
+```
+
+``devId``: I2C-Gerät / Slave Adresse.
+``Return Value``: File Handle to I2C-Bus
+
+> -1 ... Error or EXIT (Programm termination)
+
+**Example**
+>>>
+```C
+int fd = wiringPiI2CSetupInterface("/dev/i2c-1", 0x20);
+```
+
+
+### wiringPiI2CWrite / wiringPiI2CWriteReg8 / wiringPiI2CWriteReg16 / wiringPiI2CWriteBlockData
+
+...
+
+### wiringPiI2CRawWrite
+
+Writing data about an I2C slave.
+>>>
+```C
+int wiringPiI2CRawWrite(int fd, const uint8_t *values, uint8_t size)
+```
+
+``fd``: File Handle.
+``values``: Source buffer.
+``size``: Number of bytes of the source buffer that should be written.
+``Return Value``: Number of bytes that were written.
+
+**Example**
+>>>
+```C
+int fd = wiringPiI2CSetup(I2C_ADDR);
+
+if (fd > 0) {
+ uint8_t i2cvalue = 0x55;
+ int result = wiringPiI2CRawWrite(fd, &i2cvalue, 1);
+
+ if (1 == result) {
+ // 1 byte from i2cvalue send to I2C_ADDR slave
+ } else {
+ // error
+ }
+}
+else {
+ // error
+}
+```
+
+### wiringPiI2CRead / wiringPiI2CReadReg8 / wiringPiI2CReadReg16 / wiringPiI2CReadBlockData
+
+...
+
+### wiringPiI2CRawRead
+
+Reading data from an I2C slave.
+>>>
+```C
+int wiringPiI2CRawRead(int fd, uint8_t *values, uint8_t size)
+```
+
+``fd``: File Handle.
+``values``: Target buffer.
+``size``: Number of bytes that are to be read into the target buffer.
+``Return Value``: Number of bytes that were read.
+
+**Example**
+>>>
+```C
+int fd = wiringPiI2CSetup(I2C_ADDR);
+
+if (fd > 0) {
+ uint8_t i2cvalue;
+ int result = wiringPiI2CRawRead(fd, &i2cvalue, 1);
+
+ if (1 == result) {
+ // 1 byte received from I2C_ADDR and stored to i2cvalue
+ } else {
+ // error
+ }
+}
+else {
+ // error
+}
+```
+
+
+## SPI - Bus
+
+...
\ No newline at end of file
projects / 0xmirror / WiringPi.git / commitdiff